Steelmaker Siderar (SID.BA) led the MerVal's losses, falling 3.3 percent to 25.10 pesos a share, while power transmission company Transener (TRA.BA) led gains, rising 6 percent to 1.06 pesos a share.

Argentine debt traded locally dipped 0.2 percent on average in over-the-counter trade, a day after the government bought back just $3.2 million worth of bonds in a formal auction.

The dollar-denominated Boden 2014 ARBODEN14D=RASL took the biggest hit, with its ask price falling 2.25 percent.

Traders said the fact that not many bondholders tendered their paper at current prices was a positive sign, showing they were willing to hold onto the debt despite recent turbulence.

The peso closed mixed, slipping 0.16 percent against the dollar to 3.0300/3.0325 ARS=RASL in interbank transactions and firming by the same percentage to 3.0625/3.0650 ARSB= in informal trade between foreign exchange houses, as measured by Reuters. (Reporting by Jorge Otaola and Walter Bianchi; Writing by Hilary Burke)